Experimental Study on the MBR treatment of wastewater from Stevia sugar extraction

Wastewater produced during the Stevia sugar extraction process contains high concentration of organic matter. The COD_Cr is still on 1000 mg/L or more with traditional biological treatment process, it is not good. In this experiment, we treat this kind of wastewater by MBR process. The actual operation results show that COD_Cr removal rate was up to 90.9%, TN-, TP removal rates reached 95.66%, 87.86% when we control dissolved oxygen concentration of 5 ~ 6 mg/L, hydraulic retention time in 20 hours. This MBR process has many advantages, such as stable running, good effluent, small occupation area, and simple operation.